parker



Jan- 31, 1956 H. w. PARKER l2,732,923

VENDING MACHINE V IIIIIIIIIIIIHHI l llll ATTORNEY H. w. PARKER 2,732,923

VENDING MACHINE 2 She-ze'cs-Sheecl 2 N mm mw WOA wm n -w MA VlwUNM..MQQWIWQwMwIMW Il M w/ v /h u.\ QL .GBS WWWW MWM. "Sw @m AmC? @m wlVOIm .Alum .mm Vwmwm -fi S -Ism m @MNM mmm. @bum Rm NN W mm @Y W IIT AkQ SS@ @5mm Sa Sq M\ /N\ Jan. 3l, 1956 Filed April 17, 1952 UnitedStates Patent O VENDEN@ MACHENE Henry W. Parker, Flushing, N. Y.,assigner to Sylvania Electric Products Inc., a corporation oMassachusetts Application April 17, 1952, Serial No. 232,836

1S Claims. (Cl. 1941-7) The present invention relates to vendingapparatus, and more particularly to an automatic coin controlled vendingmachine having an electrical control circuit.

Most present day coin controlled vending machines are usuallymechanically operated under control of a single coin. The more advancedmechanical types are capable of making only certain limited combinationsof change from any one coin by some relatively inflexible mechanism.Further development of mechanical vending machines to accept pluralcoins of various denominations and thereafter to make correct changewould necessitate the construction of intricate and exceptionallyexpensive machines. In the event that it became necessary or expedientto vary the price of the article to be delivered by a particular vendingmachine, the resultant structure would become still more complex. itbecomes apparent that a mechanical vending machine constructed toincorporate the foregoing desirable features would have to be designedto operate under a Vast number of conceivable combinations of receivedcoins, price, and change to be delivered and hence would be expensive,bulky, complicated, and exceptionally diicnlt to service and maintain.

Accordingly, it is an object of the present invention to provide an'electrical coin controlled vending machine which will avoid or minimizethe above mentioned disadvantages and is relatively simple inconstruction and etiicient in use as compared to a conceivablemechanical counterpart.

It is another object of the present invention to provide an essentiallyelectrical control for a coin operated vending machine.

It is a further object of the present invention to provide anelectrically controlled coin operated mechanism which dispenses any itemsuch as standard package goods in response to the insertion therein ofcoins of various denominations and in an amount equal to or greater thanthe price of the goods, the mechanism returning the proper amount ofchange when necessary.

It is a further object of the present invention to provide an automaticarticle vending machine of the aforesaid character, which can be leftunattended and may be operated at any hour of the day or night todispense the articles and make correct change.

A still further object of the present invention is the provision of acontrol circuit for a coin operated vending machine which electricallyevaluates the coin or coins deposited therein in comparison to the priceof the article to be delivered, and causes the machine to operate whenthe money deposited is equal to the price or when the money deposited isequal to the price plus the change to be returned to the customer withthe article.

A still further object of the present invention is the provision of acoin operated electrically controlled vending machine whichinstantaneously sums the monetary value of coins inserted thereinregardless of their denomination and balances the sum against the priceof the article to be delivered, whereupon the machine dispenses ICC thearticle and further returns the proper amount of change.

The foregoing objects, and others will be apparent from the followingdetailed description of an illustrative embodiment. Certain of theobjects are attained by this embodiment of the present invention byapplying the concept that the combined admittance of a large number ofimpedance elements, when connected in parallel, is equal to the sum ofthe admittances of the individual elements. In this embodiment of theinvention, there is provided a Wheatstone bridge network which includesan inserted coin arm having an impedance variable as a function of thenumber and denomination of the coins inserted into the machine. Thisinserted coin arm impedance embodies a plurality of impedance elementseach of which has anadmittance corresponding to a coin of predetermineddenomination. Certain of these elements are connected in parallel as anarm of the bridge in dependence on the number and value of therespective coins inserted into the machine and represent Vaninstantaneous sum of the monetary value of the inserted coins.

The bridge network further includes a price component having animpedance value selected to correspond to the price of the article beingdispensed. This price impedance is preferably selectively settable tofacilitate the coverage of a relatively wide price range by a singlevending machine. A calibrated manual control may be provided for thepricecomponent to permit flexible,

arbitrary price adjustment by the storekeeper or serviceman aspredetermined by the values of the particular articles being dispensedby the machine from time to time.

Shunted across the price component, is a change component having animpedance which is variable and balances the bridge network when thecombined admittance of the price and change components have apredetermined value as compared to the admittance of the inserted coinarm impedance. Any suitable nullseeking servo-mechanism is controlled bythe bridge network and controls the change impedance by adjusting itsadmittance to balance the bridge network.

Accordingly, a broad feature of the invention is the provision of anelectrical bridge adapted to take price, tendered coin, and change intoaccount in controlling a vending machine. A more specific aspect of thisis the provision of price and change impedances combined as one arm of abridge circuit and adjusted, by a selfbalancing bridge servo-drive, intobalance with the impedance of the inserted-coin arm of the bridgecircuit.

The illustrative bridge network provides an essentially electricalcontrol for the dispensing machine which evaluates the coins inserted incomparison to the price of the article to be dispensed. If the value ofthe coins inserted is exactly equal to the price of the article, thebridge circuit will be balanced. However, if the value of the coinsinserted is greater than the price, the bridge circuit will momentarilybe unbalanced, whereupon the null-seeking servo-mechanism operates torebalance the network by adjusting the change impedance. The adjustedvalue of the change impedance is a measure of the proper amount ofchange to be delivered along with the article dispensed. The presentinvention may be more fully understood by referring tothe followingdetailed description of the illustrative embodiment of the invention, inwhich reference is made to the accompanying drawing, wherein:

Fig. y1 schematically illustrates a preferred embodiment of the coincontrolled vending machine of the pres ent invention; v

Fig. 2 schematically shows the embodiment of Fig. 1 in greater detail;and

Fig. 3 is a graphic illustration of the development for an actuating camwhich forms a part of the mechanism in Fig. 2.

Figs. 1 and 2 represent a, preferred embodiment of the coin operatedvending machine of the present invention. The machine includes a controlcircuit network 11 constituting a specialized form of Wheatstone bridge.This bridge utilizes the concept that the conductance of a number ofresistors in parallel is equal to the sum of the conductances. Theapplication of this concept permits the instantaneous addition of anumber of con* ductances corresponding to the monetary value of theinserted coins; and the concept also facilitates adding the conductancerepresenting price to the conductances representing coins to bedispensed as change. Speciiically, the control or bridge circuit 11includes a pair of ratio arms 12, 13 which are preferably of equalconductance. Further the circuit 11' embodies a resistive inserted-coinarm 14, the conductance of which varies as a function of the monetaryvalue of the money presented. Connected in series with the inserted-coinarm 14 is the fourth arm of the bridge circuit, including a resistiveprice component 15 whose conductance is variable in accordance with theprice of the article to be dispensed, and a resistive change component16, whose conductance is to be varied in balancing bridge circuit 11. Asuitable source of potential 17 energizes the bridge circuit.

It is apparent, that the bridge circuit 11 is balanced when theinstantaneous sum of the conductances of the shunted price and changecomponents 15, 16 is equal to the conductance of the inserted-coin'arm14. Accordingly, there is provided a control means which instantaneouslycompares the value of the money presented with the price of the articleor goods being dispensed.

Connected to the bridge network 11 is a suitable nullseekingservo-mechanism 30 whose mechanical output is coupled to the changecomponent 16 for adjusting the conductance of the latter to balance thebridge network 11. The adjusted change component 16 will give anaccurate measure of the proper amount and the denominations of thechange to be returned, as will be seen.

Specific reference will now be made to the details of the inserted-coinand price components 14, 15. The inserted-coin" arm 14 preferablyincludes a plurality of banks of resistors 1S, 18', the resistors ofeach bank having conductances corresponding respectively to coins ofseveral denominations. Each of the resistors 1S, 18 has one leadconnected to a common conductor 19, and has the other lead connected toa suitable contact 20, 20'. The contacts 26, 20 are arranged along theindividual coin chutes 21, 21 which communicate with the main coin chute22. The lower end of the individual coin chutes 21, 21 are provided withconductive base plates 23, 23. These chutes and base plates areconnected via lead 24 to the common terminals of the price and changecomponents 15, 16. The widths of the respective coin chutes 21, 21 areselected and arranged to sort and receive only coins of the respectivedenominations. The individual chutes 21, 21 are arranged at spacedintervals along the main chute 22 and progressively increase in width`at locations spaced further from the intake end 22a of the main chute22. For example, the chute 21 may receive dimes as coins of the smallestdiameter, and the chute 21 may receive pennies, coins of the next largerdiameter. This arrangement assures the automatic selection of theresistors of the proper banks 18, 18' for connection into thewbridgecircuit 11. The respective resistors of each bank, which correspond tothe same monetary value, are connected into the circuit 11 over aconductive path which in the illustrative apparatus includes the coinsof the same denomination. Preferably the value of each of the resistorsof the banks 18, 18' is high as compared to the resistance of therespective coin to thereby minimize errors due to variations in theresistance of the coins and contacts 20, 20. In lieu of the arrangementwhere the circuit is completed through the metallic coin itself, thecircuit can be completed through contacts mechanically closed by theinserted various coins.

A practical embodiment for example includes fty resistors representingpennies and each having an irnpedance of ohms, ten resistorsrepresenting dimes and each having an impedance of l0 ohms,tworesistances representing quarters and each having an impedance of 4ohms, and one resistor representing a half dollar and having animpedance of two ohms. In this example, the respective conductancevalues are numerically equal to the dollar value of the representedcoins.

in the price" component 15, a single calibrated variable resistance maybe employed, or as illustrated, aplurality of separate resistors 25 maybe connected to a common lead 26 and selected by a movable contact 27.The conductance values of the resistances can be selected to correspondto the various prices. For example, a two ohm resistor having aconductance of .5 ohm could represent a price of ifty cents. By thissimple arrangement, the storckeeper can select a desired price andthereafter lock the contact 27 in place.

The null-seeking servo-mechanism 36 of the control circuit 11 has inputconnections respectively to the potential reference point at thejunction of resistors 12 and 13, and to the junction of inserted-coinarm 14 with the arm consisting of the price and change components 15 and16. This servo-mechanism conventionally includes a high gain electricalamplifier and a motor having mechanical output in response to theelectrical input produced by the bridge circuit. This servo-mechanism ismechanically coupled to adjust the changelcomponent of the bridgecircuit until balance of the bridge is effected. Advantageously, also,the servo-mechanism can be arranged to initiate an article dispensingcycle. For example, a trigger circuit 31 may be operated in response tobalancing of the circuit 11 and connected to an article delivery device32 of proper design for delivering a single article as soon as theservo-mechanism 31B balances the circuit 11. Trigger 31 conveniently maytake the form of a slow-acting relay connected to a source of potentialand having open-circuit contacts so long as it is energized by theelectrical output of the servo amplifier. When the bridge is balanced,the amplifier output decays and the relay contacts close to connect thesource of potential to the device 32. As shown in Fig. 2, the deliverydevice -32 may include a one revolution drive 33 coupled through asuitable reduction gear 34 and drive gear 35 to an actuator 36 arrangedwithin the delivery chute 37. In response to the closing of theopen-circuit contacts of the trigger circuit 31, the one revolutiondrive 33 operates to index the actuator 37 and releases an article toenter the delivery chute 37.

Further, circuit 11 is connected to control a change dispensingmechanism 40 which returns the proper amount of change to the customeralong with the goods. Referring now to Figs. 2 and 3, there isillustrated in greater detail, one embodiment of the change component 16of the bridge circuit and the change dispenser di), both of which areregulated by the servo-mechanism 30.

For the sake of clarity and simplicity, the change component 16 has beenshown to include several penny resistors 41a, a single nickel resistor41b, two dime resistors 41C, and a single quarter resistor 41d. Thesechange resistors represent the banks of resistors appropriate to controldelivery of an appropriate combination of coins.

It can be demonstrated that all the requisite amounts of change up toone dollar can be made by a change" bridge component 16 including nineresistors, namely,

four penny resistors, one nickel resistor, two dime resistors, onequarter resistor, and one fty cent resistor. In the simplilied showingof Fig. 2,ithe 50 cent control is omitted. Resistors 41a, 41b, 41cvandv41d have one side connected` to a common lead 42 which is connected tothe proper terminal ofthe price resistor 15. The other side of therespective change resistors are connected to associated leaf-springswitches 43a, 43b, 43e and 43d. These switches are of the single-polesinglethrow type and are actuated by the control cams 44a, 4411, 44C and44d, which are adjusted by the servo-mechanism 3d. In response to theclosing of contacts dSa, 45h, 45e and idd of the switches 43a, 43h, 43Cand 43d, the change resistors 41a, ll'lb, 41C and 41d are connected inparallel withV each other and with the price resistor 15. The additionalcams and switches associated with additional resistors 4ta and llc havebeen omitted for clarity.

Referring now to Fig. 3, there is shown a graphic illustration of a camdevelopment suitable for a change bridge component 16. The variouschange amounts are -plotted on the abscissa and the switch positionsplotted on the ordinates. lf, for example, the amount of change to bereturned is thirty-two cents, then the change will be made up of twopennies, one nickel, and one quarter, and the various cam portions willoperate switches for connecting two penny resistors, one nicke resistorand one quarter resistor into the circuit as parallel resistors, thiscombination being apparent at 32 of Fig. 3. in lieu of cams 44 for theswitches 43, a perforated drum and associated pins or contacts may beemployed for closing the appropriate switch contacts 45, and otheralternatives will occur to those skilled in the art.

Once again referring to Fig. 2, the structure of an illustrative changedispensing mechanism 40 will now be described. This mechanism includesthe change dispensing chutes 50a, 50h, 50c, 50d, each of which stores asupply of coins of the same denomination. A diagrammatically illustratedescapement mechanism 51a, 51h, 51e

and Sie! is associated with the respective dispensing chutes v 50a,5011, Stic and 50d to permit coins to drop into a cornmon change return,not shown. The escapement mechanisms operate after the connection of thechange resistors of the related denominations into the bridge circuit 11and in response to balancing of the bridge circuit. Each of theescapement mechanisms 51a, 51b, 51e, 51d includes a pair of spacedslides 52, 53 interconnected by a linkage 54, the latter having pivots55. A suitable spring 56 is connected to one end of each of therespective linkages 54 to bias the linkages into an inoperative`position shown, wherein the slides 5,2 are drawn back out of theadjacent one of dispensing chutes 50a, Sb, 50c, Sila' and the slide 53traverses the open mouth of the adjacent dispensing chute. lOperativelyconnected to the other ends of the linkages 54 are the armatures 57a,57b, 57e and 57d of solenoids 58a, 58b, 58C, and 58d. The armatures 57d,57h, 57C and 57d are drawn back in response to the energization of thesolenoids and momentarily reverse the position of the slides 52, 53permitting the lowermost coins to drop into the coin return andthereafter allowing the next coin to fall into position to besubsequently delivered. The solenoids 58a, SSb, 58o and 58d areenergized through the contacts 59a, 59h, 59e and 59d of the associatedswitch 43a, 43h, 43e and 43d, which in turn are connected to the triggercircuit. Instead of the solenoids 58a, 58h, 58C and 58d and theescapement mechanisms Sla, 51b, 51e and 51d connected thereto, any othersuitable arrangement may be employed which may be set in accordance withthe setting of the change bridge component 16 to deliver the properamount of change when the bridge circuit 11 is balanced.

In operation, the storekeeper sets the price resistor to correspond inconductance to the price of the article to be delivered. After loadingthe machine 32 with items to be delivered and filling the changedispensing chutes A50, the device may be left unattended. The

6 bridge circuit is unbalanced since the price" component diiers fromthe inserted coin arm in a way that cannot be corrected by adjusting thechange bridge component. The customer inserts any combination of coinsinto the machine. These coins fall into the appropriate chutes 21. Whenan insufficient number of coins are inserted, the control circuit 11remains unbalanced. If the value of the inserted coins is equal to theprice of the article, the bridge circuit 1l Will be balanced, the inputto the servo-mechanism 3G will be zero, and there will be no necessityfor the device to make change. The trigger circuit 31 then will energizethe delivery device 32 and a single article is delivered at chute 37.The

inserted coins are released for delivery to an internal container bysuitably releasing plates 23, 23', and the machine is ready for a newcycle.

In situations where the customer inserts changein an amount greater thanthe price, the bridge circuit 11 will be momentarily unbalanced and thenull-seeking servomechanism 3i) will be energized in a polarity or senseenabling this servo-mechanism to adjust cams 44 until balance of thebridge is restored by connection of appropriate resistors il throughswitches 43 in parallel with price resistor 15. Simultaneously with theselection of the change arm resistors 4i, the change dispenser 4G ispreset. When the balance condition is reached, the trigger circuit 31enables the dispensing mechanism 32 to deliver the article and alsooperates the change dispenser 49.

There has been described a widely adaptable, effective, electricallycontrolled, coin operated vending machine, which automatically evaluatesthe coins inserted and delivers an article of a predetermined price,together with change when necessary.

While in accordance with the provisions of the statutes, I haveillustrated and described the best form of embodiment of my inventionnow known to me, it will be apparent to those skilled in the art thatchanges may be made in the form of the apparatus disclosed'withoutdeparting from the spirit of my invention as set forth in the appendedclaims and that in sorne cases certain features of my invention may beused to advantage without a corresponding use of other features.

What l claim is:

1. A coin controlled vending machine, comprising coin receiving means, acircuit network including `a first impedance controlled by insertedcoins and variable in accordance with the value of coins inserted insaid coin receiving means, a second impedance having a value selected inaccordance with the price of the article to be delivered, and a thirdimpedance variable to balance said network, a null-seekingelectromechanical drive connected `to said network and controlled by theunbalance thereof and operatively connected to said third impedance tobalance said network, means dispensing values of coin change undercontrol by said drive and responsive to the balancing of the networkafter adjustment of said third impedance for returning change in anamount corresponding tothe adjustment of said third impedance, andarticle dispensing means operable in response to balancing of saidnetwork for delivering said article 2. A coin controlled vending machineaccording to claim l, wherein said impedances are resistive elements.

3. A coin controlledV vending machine according to claim' 2, whereinsaid first impedance is connected as one arm of a bridge circuit andsaid second and third impedances are connected as another arm of abridge circuit.

4. A coin operated vending machine, comprising coin receiving means, acircuit network including an insertedcoin component controlled byinserted coins and variable in impedance in accordance with the numberand denomination of the coins inserted in said coin receiving means, aprice component variable in impedance in accordance with the price ofthe article to be vended, and a change component variable in impedanceto balance said network, a null-seeking servo-mechanism having inputconnections to said network and operatively connected to said changecomponent, means dispensing values of coin change under control by 'saidservo-mechanism and responsive to the balancing of said network afteradjustment of the impedance of said change component for returningchange in an amount corresponding to the adjusted impedance of saidchange component, and article dispensing means operable in response tobalancing of said network for delivering the article.

5. A coin operated vending machine, comprising coin receiving means, abridge circuit including a potential divider having a predeterminedratio, a resistive inserted-coin arm controlled by inserted coins andvariable in accordance with the number and denomination of the coinsinserted in said coin receiving means, resistive change and pricecomponents in said bridge circuit and arranged to balance said bridgecircuit when said change and price components combined are related tosaid inserted-coin arm in the same ratio as that of said potentialdivider, a null-seeking servo drive energized under control of `theunbalance of said bridge and operatively connected to said changecomponent for adjusting the latter to balance said bridge circuit, meansdispensing values of coin change under control of said drive andresponsive to the balance of said bridge circuit after adjustment of theconductance of said change component for returning change in an amountcorresponding to the adjustment of said change component, and articledispensing means operable in response to balancing of said bridgecircuit for delivering the article to be vended.

6. A coin operated vending machine according to claim 5, wherein saidchange and price components are connected in parallel with each other asone arm of said bridge circuit and'in series with said inserted-coinarm.

7. A coin operated vending machine according to claim 5, wherein saidinserted-coin arm includes at least one bank of resistors eachconnectable into said bridge circuit over a conductive path includingthe respective coins inserted into said coin receiving means, the valueof each of said resistors being high as compared to the resistance oftherespective coins.

8. A control circuit for a coin operated vending machine, comprisingcoin receiving means, a circuit network including a first impedancecontrolled by inserted coins and variable in accordance with themonetary value of coins inserted in said coin receiving means, a secondimpedance adjustable to correspond to the price of the article to bevended, a third impedance variable to balance said network, andadjusting means operable in response to unbalance of said network andoperatively connected to said third impedance to balance said network.

9. A control circuit `according to claim 8, including change makingmeans adjusted by said adjusting means coordinately with said thirdimpedance.

10. A control circuit according to claim 8, wherein said tirst impedanceincludes a plurality of banks of resistors, the resistors of each bankindividually having a value of conductance corresponding to a selectedone of several denominations of coins.

11. A control circuit according to claim 8, wherein said third impedanceincludes a plurality of resistors each having a conductancecorresponding to a coin of predetermined denomination.

12. A control circuit for a coin operated vending machine, comprisingcoins receiving means and a bridge circuit including an inserted-coinarm having a conductance controlled by inserted coins and variable inaccordance with the number and denomination of coins inserted in saidcoin receiving means, change and price components in said bridge circuitconnected in parallel and arranged to balance said bridge circuit whentheir cornbined conductance has a predetermined ratio to the conductanceof said coin arm, and null-seeking, adjusting means energized by saidbridge circuit and operatively connected to said change component foradjusting the latter to thereby balance said bridge circuit.

13. A control circuit according to claim 12, wherein said inserted coinarm includes a plurality of banks of resistors, the resistors of eachbank being arranged for connection in parallel and individually having avalue of conductance corresponding to a selected one of severaldenominations of coins.

14. A control circuit according to claim 13, including contact meansoperatively connected to the respective resistors of said banks andoperable under control of the inserted coins to connect the respectiveresistors into said bridge circuit.

15. A control circuit for a coin operated vending machine, comprising a'circuit network having a first impedance for unbalancing said circuitnetwork in accordance with the value of coins inserted in said machine,said first impedance including at least one bank of resistors eachhaving a conductance corresponding to a coin of one denomination, atleast one coin chute constructed to receive coins of said onedenomination, a second impedance corresponding to the price of thearticle being vended and connected in said circuit network, a thirdimpedance in said circuit network for balancing said circuit network,contact means constructed and arranged to connected the respectiveresistors of said bank into said circuit network under control of thecoins inserted into said coin chute, and adjusting means operable inresponse to unbalance of said circuit network and operatively connectedto said third impedance for balancing said bridge network.

16. A control circuit according to claim 15, wherein said Contact meansincludes a plurality of spaced apart contact elements arranged alongsaid coin chute, each of said contact elements being connected to aresistor of said bank for connecting said resistor into said bridgecircuit over a conductive path including one or more coins inserted insaid coin chute.

17. A control circuit according to claim 16, including manually operablemeans for adjusting the value of said second impedance.

18. A control circuit according to claim 15, wherein said thirdimpedance is connected in parallel with said second impedance and inseries with said iirst impedance.

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